Dynamo-electric machine



(No Model.) 2 Sheets-Sheet 1.

1). HI'fiAM.

DYNAMO ELECTRIC MAGHINE. No. 399,404. Patented Mar. 12, 1889.

WITNESSES: /IVVEI;0Z QM a ATTORNEYS,

(No Model.) 2 Sheets-Sheet 2.

D. HIGHAM.

DYNAMO ELECTRIC MACHINE. No. 399,404. Patented Mar. 12, 1889.

i fl- 5 Kw 1 27" MWXT' W, M Q5 Q7,

WITNESSES: INVENTOR,

' ATTORNEYS,

UNITED STATES PATENT Qrricn.

DANIEL HIGHAM, OF PHTLADELPHIA, PENNSYLVANIA, ASSIGXOR TO THE HIGHAM ELECTRTC LIGHT ((TDIPANY, ()F ROCKLAND, MAINE.

DYNAMIC-ELECTRIC MACi-HNE.

SPECIFICATION forming part of Letters Patent No. 399,404, dated March 12, 1889.

Application filed July 7, 1888, Serial No. 279,315. (No model.)

To (/ZZ (P710727 it may concern:

Be it known that I, DANIEL lliGi-iAM, a citizen of the l'nited States, and a resident of Philadelphia, Pennsylvania, have invented Y certain Improvements in Commutating Devices tor l)ynamo-Electric Machines, ot which the following is a specification.

My invention relates to the commutating devices for dynamo-electric machines and electric motors, my invention consisting of certain improvements in the construction of the commutator, the brushes, and the brushholding devices, as hereinafter descriljied.

In the accompanying drawings, Figure]. is a side View showing the commutz'itor, the brushes, and the holders for the latter. F' g. 2 is a longitudinal section through the commutator on the line 1 2, Fig. i. Fig. 3 is an end view of the commutator holders and brushes looking in the direction of the arrow,

Fig. 1; and Fig. 4c is a side view ol one of the connnutator-bruslies detached.

The commutator is made up ot a numberof metallic segments, A, as usual, which are separated from each other at their bases by insulating-blocks Z), and toward the periphery of the commutator by air spaces or slits a. The segments and intermediate insulatingblocks are clamped between a ring, d, formed by a flange on the sleeve D, and a ring, 61, secured to the sleeve at the opposite end, this sleeve being keyed or otherwise secured to the shaft S of the armature in the usual way. Rings or washers r of insulating material are placed between the segments and the clamping-rings, by which they are held, as shown in Fig.

As usually constructed, the clamping-rings for the segments are nearly equal in diameter l thermorc, I extend the slits a down into the insnlating-blocl s I), as shown in Fig. 1, so that even if tine particles of metal he accidentally left in the bottoms of the slits theyean do no harm.

The mmmutator-brnslies E are held in clamps t, pivoted to curved adjustable holders 1 which are secured to arms t; on the base of the machine. The adjustable holders F are curved on a radius drawn from the center of the armature-slmtt, and the bearing-faces of the arms G are similarly curved on similar lines. The curved holders 15 are held to the curved bearing-faces ot' the arms G by means of headed bolts f, passing through slots (indicated by dotted lines in Fig. 1) in the curved holders 1, so that by loosening these boltstheholders and brushes can be adjusted readily to any desired position, and as the ends of the commutatorbrushes wear away their point ot' contact on the commutator(an always be maintained by the described adjustment.

The ends of the commutatorbrnshes are curved, as shown in Fig. 1, so as to maintain a proper bearing upon the segments.

Each brush E is made of two strips, 1:, and slitted, as shown in Fig. 2.3. The bearing ends of the brushes are beveled, as shown in Figs. 3 and a, on their adjacent inner faces, so that the bearing-faces of the individual members or points of each brush are of different thicknesses. By preference the greatest thickness is at the center, while the outer edges of the brushes are thinnest. The object of this is to lessen the sparking, which is caused by the jumping of thebrushes when the machine is in operation.

By making the lamina: or individual points of each brush of different thicknesses a diffcrent wearing effect upon the different parts of the edges of the comimitator-segments is obtained, and in consequence, although the members of each brush leave one segment all atthe same time, and also pass onto the next segment all at the same time, (owing to the straight front and back edges of the brnsh,) yet the bouncing up of the points from i the face of the commutator, which is more apt i to occur on a sudden increase of speed, will ,ferent times.

take place, as to the different points, at dif- As the points of a brush are thus never all bounced up at once, there is little or no sparking from this cause.

The beveling oit ot' the brushes, as described, causes the individual members of each brush to jump at different times, instead of at the same time, as would be the case if they were all of the same width, and in this way the tendency to sparking is lessened.

'lhe brushes are caused to bear upon the 1 commutator surface by means of curved springs s, hooked at the ends into loops 1, one

in each case upon the clamp and the other This eonstruction of spring permits the brush to be thrown uponthe adjustable holder.

back to the position indicated by dotted lines in Fig. 1, so that when it is turned back to that position it will stay there until it is intentionally returned to bear upon the scg- I claim. as my invention 1. A commutator having segments and intermediate insulating-blocks with air spaces i or slits extending down into the intermediate l l l insulating-blocks, and clamping-rings not. covering the ends of the slits, as and for the purpose set forth.

2. A commutator having segments with insulating-blocks and air-spaces, and clampingrings not covering the ends of the air-spaces, as and for the purpose described.

A commutater-brush composed of two strips having the bearing ends of the individual members or points of different widths, as and for the purpose set forth.

-t.. The combination of a commutator, with 1. pair of commutator-brushes set out of line for bearing upon independent portions of the eonnnutator, substantially as set forth.

In testimony whereof I have signed my name scribing witnesses.

. DANIEL HIGHAM.

Witnesses:

l l-lUiBERr HOWSON,

i HARRY SMITH.

to this specification in the presence of two sub- 

